<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin:0;
            padding:0;
        }
        div.beijing{
            width: 900px;
            height: 600px;
            background-color: red;
            position:relative;
            margin:100px auto;
        }
        div.wujiao {
            position: relative;
            display: block;
            width: 0;
            height: 0;
            border-left:100px solid transparent;
            border-right:100px solid transparent;
            border-bottom:70px solid yellow;
        }
        div.wujiao::before {
            content:'';
            position: absolute;
            top:-63px;
            left:-37px;
            display: block;
            width: 0;
            height: 0;
            border-top:100px solid transparent;
            border-bottom:100px solid transparent;
            border-right:70px solid yellow;
            transform:rotate(19deg);
        }
        div.wujiao::after {
            content:'';
            position: absolute;
            top:-63px;
            left:-37px;
            display: block;
            width: 0;
            height: 0;
            border-top:100px solid transparent;
            border-bottom:100px solid transparent;
            border-left:70px solid yellow;
            transform:rotate(-19deg);
        }
        div.x1{
            position:absolute;
            top:180px;
            left:85px;
            transform:rotate(36deg) scale(1);
        }
        div.x2{
            position:absolute;
            top:71px;
            left:247px;
            transform:scale(0.3) rotate(10deg);
        }
        div.x3{
            position:absolute;
            top:136px;
            left:300px;
            transform:scale(0.3) rotate(20deg);
        }
        div.x4{
            position:absolute;
            top:205px;
            left:296px;
            transform:scale(0.3) rotate(45deg);
        }
        div.x5{
            position:absolute;
            top:265px;
            left:255px;
            transform:scale(0.3) rotate(60deg)
        }
        
    </style>
</head>

<body>
    <div class="beijing">
        <div class="x1">
            <div class="wujiao"></div>
        </div>
        <div class="x2">
            <div class="wujiao"></div>
        </div>
        <div class="x3">
            <div class="wujiao"></div>
        </div>
        <div class="x4">
            <div class="wujiao"></div>
        </div>
        <div class="x5">
            <div class="wujiao"></div>
        </div>
    </div>
</body>

</html>